1. Field of Invention
This invention relates to systems and methods for improving marking device speed and/or resolution.
2. Description of Related Art
A common design problem in the field of printing devices is how to increase printing speed without sacrificing image resolution or contrast. Typically, to increase the speed of a printing device, the image resolution of the printing device is lowered. This allows the print head to travel more quickly across each scan line because it does not have to eject ink or toner at as many locations along that scan line. Another conventional method for increasing the speed of a printing device is to decrease the number of times a print head must pass over the same scan line. For instance, when a conventional printing device is utilizing what is popularly called the draft mode, the print head only makes a single pass per scan line, increasing the output speed, but decreasing the image contrast due to the lower amount of ink on the page.
Conventional printing systems utilizing four-color printing (cyan, magenta, yellow, and black) have approached the output speed design problem of increasing black and white printing speed by utilizing “four-color black” printing. In four-color black printing, an amount of cyan, magenta, and yellow are first ejected by the print head and then covered with black. By printing cyan, magenta, and yellow under black, conventional four-color printing systems are able to increase the density of ink ejected in a single scan line pass of the print head. Because the ink is ejected in layers, image defects that result from merely ejecting a large amount of a single color at once do not occur. In this manner, conventional four-color black printing utilizes the increase in output speed that results from single scan line pass printing without sacrificing image contrast.